The present invention concerns a novel method for loading railroad cars coupled in motion.
Over the last few years, the need to load railroad cars to their optimum carrying capacity has become increasingly apparent. Escalating railroad maintenance costs have driven railroads to adopt a much stronger position on overloading, often to the point of refusing to haul overloaded cars or imposing significant financial penalties. At the same time, freight costs are frequently based on minimum loads. In other words, freight is charged on the capacity of the car or the actual amount carried, whichever is greater. Therefore, underloaded cars result in freight being paid for products not actually shipped.
Therefore, it is essential to load the railroad cars within close limits to avoid financial penalties. I have discovered a novel system which uses a track scale to monitor the product loaded into the car and to automatically stop the loading when the required amount has been loaded into the car. Although it has always been desirable to load railroad cars to as high an accuracy as practicable, there are many factors which are present and which effect such accuracy. These factors include errors caused by weight transfer through couplers on loadout scales and weight transfer through couplers on tare scales. Other error factors include weighing and control system response times and repeatability, the accuracy of the weighing scales (static and dynamic), the weight buildup on the scales due to spillage, the amount of product going into the car after the final cutoff, the repeatability of the loading gate response time, the consistency of the product density, the consistency of the product flow at a given loading gate opening and the time available for loading.
I have discovered a system which alleviates loading errors due to weight transfer through the car couplers and effectively provides a weighing apparatus and method with the same accuracy as a bin type loadout system. My system has the ability to operate as a net weight loading system and can also be readily retrofitted to existing loadouts.
Other advantages of the present invention will become apparent as the description proceeds.